The Liver Metabolism Program Project (LMPP) consists of a group of closely related research projects concerned with metabolic functions of the hepatocyte. Studies of lipid, carbohydrate, protein, and collagen metabolism as well as the liver drug metabolizing system and liver cell transport processes are under active investigation. Many of the projects are collaborative and some closely interact with independently funded new research programs encouraged by the success of the LMPP. Most projects have utilized the cell culture core facility which has developed improved techniques for hepatocyte monolayer culture. This relatively new methodology has been exploited to advance understanding of metabolic and transport processes and to verify or confirm observations from other techniques, in vitro or in vivo. The emphasis during the renewal period will concern the following metabolic functions: synthesis of phospholipids and neutral lipids in response to toxins and physiological changes, control of bile acid synthesis, metabolism of liver collagen, the biosynthesis and turnover of hepatic cytochromes, the regulation of hepatic gluconeogenesis, the formation of complement proteins and the effects of agents including bile acids on transport functions of the hepatocyte. The project has: advanced knowledge of liver metabolism; attracted investigators from other fields into studies of the liver; and contributed to better exploitation of hepatic monolayer culture for metabolic studies.